Wearing apparel frequently contains air-impermeable or substantially air-impermeable material which result in the formation of sweat at the corresponding part of the body.
One such example is rain jackets or raincoats with a waterproof and air-impermeable outer layer, and an inner fiber lining. Lacking air and water permeability, the outer layer of the clothing cannot release moisture to the outside, instead it is soaked up by the lining. Since the lining is not aired due to the air-impermeability of the outer layer of the clothing, the lining cannot dry, but remains sweat-soaked, which causes a feeling of discomfort and coldness.
Another example is hats, hoods and caps which are lined with an air-impermeable outer layer. In this case also, sweat forms during wearing, which cannot escape but causes the part of the hat, hood or cap which lies against the head to become damp. This also causes discomfort for the wearer, especially a feeling of coldness. Still other examples are gloves and footwear.